Vulnerability identifier: #VU21373

Vulnerability risk: Low

CVSSv3.1: 5.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-16914

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
pfsense
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor: Rubicon Communications

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data passed via the "username" and "delmac" parameters to services_captiveportal_mac.php script. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation
Install update from vendor's website.

Vulnerable software versions

pfsense: 2.3.0 - 2.4.4_3

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External links
http://github.com/pfsense/pfsense/commit/d31362b69d5d52dc196dc72f66e830cd1e6e9a4f
http://redmine.pfsense.org/issues/9609
http://www.seebug.org/vuldb/ssvid-98023

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.